Improvement



PATENT OFFICE.

JOHN BOITES, 2D., OFBOSTON, MASSACHUSETTS.

IMPROVEM ENT IN BRIDGES.

1 Specification forming part of Letters Patent No. 48,013, dated May 30,1865.

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To all whom, it may concern:

yBe it known that I, JOHN BoLEs, 2d., of Boston, in the county ofSuffolk and State of Massachusetts, have made a new and useful inventionhaving reference to trusses for bridges, roofs, Ste.; and I do herebydeclare the same to be fully described in the following specificationand represented in the accompanying dra-wings, of which- Figure l is aside elevation of a truss constructed in accordance with my` invention.Fig. 2 is a vertical and transverse `section of it.

My invention has reference to what is termed lattice77 trusses, or thosewhich have diagonal braces and counter-braces crossing one another, soas to form quadrilateral openings at the crossings ot' four of suchbraces, such invention consisting in uniting each two straight braces ora straight brace and a counter-brace by curved or arched connections, tobe fastened to the chord at the union of such braces.

And my invention also consists in a combination of a series of diagonalstruts with the braces and counter-braces and their quadrilateralopenings, the whole being arranged substantially as hereinafterdescribed.

In the drawings, A and B are the top and bottom chords of the truss, andO G 0,8m., and D D D, Src., are the braces and counterbraces of suchtruss, they being arranged between the chords, 4so as to cross oneanother, in manner as shown in Fig. l. The foot of each brace isconnected with that of each'counterbrace D by means of an arched orcurved connection or continuation of both of such braces, the same beingas shown at a, such connection being bolted to the bottom chord. In thesame manner, if desirable, each of the braces` at its upper end, may beconnected with some one of the counter-braces. This method of connectingthe braces and counter-braces is particularly useful when they are madeof' thin iron bars, and it affords increased strength to the truss, andparticularly to the chord to which the connection may be bolted. Anothermode of carrying out my invention is lo unite eac-h two of the braces,as well as each two of the counter-braces, by means of anarch-connection, or combination ot' them, as described, there being sucha connection at the two lower parts of the braces, and, if desirable, atthe upper parts thereof. Furthermore, I arrange within each of thequadrilateralopenings of the lower range or ranges of such openings ofthe braces and counter-braces what; I term a diagonal upright strut, E,which isto overlap the braces and extend into or through its openings inmanner as shown in the drawings, and is to be bolted to the braces attheir crossings. These struts serve to prevent sagging ot' the truss.They contribute greatly to its strength, as well as to reiieve fromstrain the bolts of the crossings to which such struts are connected.They also answer other useful purposes.

Having thus described the nature of my invention and the manner ofconstructing the same,.what I claim is as follows, viz:

l. The combination 'of the series oi' arch-connections a a a, thestraight braces and counter-braces and their chord or chords, the wholebeing arranged substantially as set forth.

2. The combination of the series of diagonal upright struts E E with thesystem of braces and counter-braces and their chords, the whole beingarranged substantially1 as specified.

In testimony whereof I have hereunto set my, signature.

JOHN EoLEsQD.

Witnesses:

R. H. EDDY, F. P. HALE, Jr.

